850 Burning Oil

kr9600 · Post by **kr9600** » 04 Jan 2011, 05:37

Greetings and Happy New Year to all.

I have a 1995 850 Turbo that is burning oil but not all the time. It seems worst just after I start up and contnues for a about 3 to 5 miles. The discharge is standard blue smoke. After that it either reduces considerably or stops burning oil completely until I stop again and the cycle repeats itself. The engine seems to have plenty of power (although I have nothing to compare it with) and there is no hesitation or eratic operation. The engine has a little over 200K on it. Do you think this may be rings or valves or could it be something else? Is there a way to check whether it is valves and not the rings. I suspect a valve job might be a little easier than a ring job but I really don't know. Any assistance anyone can offer would be greatly appreciated. Thnak you.

zhenya · Post by **zhenya** » 04 Jan 2011, 07:42

Leakage at the valves are far more common on these cars than at the rings, but the way to tell is to do a leak-down test, which should allow you to determine where the leakage is coming from, and at least get a good idea if it is top-end or bottom-end. I'm sure the regular mechanics here will have some better advice for you than that though.

FWIW, my car smoked a bit at start up, and consumed at least a qt of oil every 1000 miles until I switched to Mobil 1 high mileage. It now burns less than a qt in 5k miles, and I get no smoke at start up. Might be worth a try at the next oil change.

Klausc · Post by **Klausc** » 04 Jan 2011, 10:55

Valve stem seals do leak with age, but that usually results in smoke when going down hills with the foot off the throttle (lots of vacuum). Get a compression test with a warm engine to rule out rings, etc.

It could be that the outter ring on the turbo is leaking a little oil. If so, there should be running oil at the throttle body entrance. Usually, no big deal unless someone plugged up the weep hole in the bottom of the intercooler.

bguzz · Post by **bguzz** » 04 Jan 2011, 10:59

Start with the easy stuff first. You could have stuck(coked) rings or engine buildup. I would try doing an oil change with Auto-RX before anything. It is a reputable PAO additive that slowly cleans your internal engine during the oil change interval. Lots of people, including me, have had great success with this. It certainly won't hurt.

What oil are you running and how much are you burning. You might want to move to a high mileage oil to reduce burning/consumption.

kr9600 · Post by **kr9600** » 05 Jan 2011, 14:45

Thanks so much for all of your advice. In response to a comment by Klausc, I do get most of the smoke when I take my foot off the gas or when I accelerate just after having my foot off the gas. I will try some of the additives/synthetic oil recommended and have my local garage do the referenced leak down test. Thanks again for the quick and thoughtful responses.

Post by **Red-Arrow** » 05 Jan 2011, 15:07

I have just burnt 1 quart in 3k miles but I have no blue smoke from my exhaust at all, the smog check confirmed that.

I guess its something to live with on these high milers, mines is at 220K now.

zhenya · Post by **zhenya** » 05 Jan 2011, 15:29

1qt in 3k miles?? Most NEW cars are considered in spec at 1qt/1k miles - no wonder you don't see any smoke!